Preparation and Luminescence Properties of Hybrid Materials Containing Europium(III) Complexes Covalently Bonded to a Silica Matrix

Abstract

A new kind of luminescent organic−inorganic hybrid material (denoted Hybrid I) consisting of europium 1,10-phenanthroline complexes covalently attached to a silica-based network was prepared by a sol−gel process. 1,10-Phenanthroline grafted to 3-(triethoxysilyl)propyl isocyanate was used as one of the precursors for the preparation of an organic−inorganic hybrid materials. For comparison purposes, the hybrid material (denoted Hybrid II) in which phenanthroline was not grafted onto the silica backbone of the frameworks was also prepared. Elemental analysis; NMR, FT-IR, UV/vis absorption, and luminescence spectroscopies, and luminescence decay analysis were used to characterize the obtained hybrid materials. It is shown that the homogeneity of Hybrid I is superior to that of Hybrid II, and a higher concentration europium can be incorporated into Hybrid I than Hybrid II. Excitation at the ligand absorption wavelength (283 nm) resulted in the strong emission of the Eu3+ 5D0−7F J (J = 0−4) transition lines as a result of the efficient energy transfer from the ligands to the Eu3+ in Hybrid I. The number of water molecules coordinated to the europium ion was estimated, and the structure of the as-synthesized Hybrid I was predicted on the basis of the experimental results.

Novel luminescent materials based on silica doped with an europium(III) complex of 2,6-dihydroxybenzoic acid

“…The photoluminescent behaviour of these complexes incorporated in solid matrices is very interesting. The preparation of silica composites containing luminescent complexes seems a promising strategy, since the resulting materials can be prepared at room temperature by employing the sol-gel method, hence avoiding thermal degradation of the complex [4][5][6][7][8]. The SiO 2 matrices also have good mechanical and chemical stability, optical transparency, and are easily prepared using well-known procedures.…”

Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

“…Curve 2 in Figure 2 shows the FTIR spectrum of TDI modified silica (SiO 2 -TDI), compared with the spectrum of the unmodified silica, the TDI modified silica exhibited peaks at 2273, 1653, 1605, 1545 and 1472 cm −1 in addition to the peaks of original silica. The peak at 2273 cm −1 can be attributed to the ortho-isocyanate groups of TDI attached to the silica surface, while the bands at 1653 and 1545 cm −1 can be reasonably assigned to the group of -CONH-formed in the reaction [22] , the peaks at 1605 and 1472 cm −1 are reasonably attributed to the phenyl ring of TDI. In addition, the absorbance of surface hydroxyl group became quiet weak.…”

Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer

“…Curve 2 in Figure 3 shows the FTIR spectrum of TDI modified silica (SiO 2 -TDI), and compared with the spectrum of the unmodified silica, the TDI modified silica exhibited peaks at 2273, 1653, 1605, 1545 and 1472 cm −1 in addition to the peaks of original silica. The peak at 2273 cm −1 can be attributed to the ortho-isocyanate groups of TDI attached to the silica surface, while the bands at 1653 and 1545 cm −1 can be reasonably assigned to the group of -CONH-formed in the reaction [21] , and the peaks at 1605 and 1472 cm −1 are reasonably attributed to the phenyl ring of TDI. The results clearly confirmed that the TDI molecule was covalently linked to silica particles, suggesting successful surface modification of the silica particles with TDI.…”